Many pharmaceutical and food preparations are made by blending two or more powders together prior to further processing, such as compression into tablets or filling capsules, bottles, pouches, etc. Such powder blending must be thorough in order to avoid irregular distribution of the ingredients which equates to inconsistency in product quality. To verify uniformity of the powder blend, testing of powder properties must be conducted at the completion of the blending cycle prior to further manufacturing processes. The first step in testing is the acquisition of samples of a uniform size from various areas in the production batch for comparison with a standard.
If one of the ingredients in the blend is an active ingredient, such as a drug, deviation from the standard component ratio will render the dosage form non-uniform and potentially ineffective or dangerous. Therefore testing of powder blends for uniformity prior to further processing, handling, shipping, etc. is imperative. Uniformity in powder blends is usually studied both at the research and development stage and at the manufacturing stage by obtaining samples of the finished product, such as tablets or capsules. Samples are obtained at different time intervals throughout the processing batch and analyzed for content uniformity. However, since uniformity of the tablet or capsule is derived from uniformity of the powder blend, it is more efficient to test the powder blend, especially during production operations.
Thus, an apparatus to test powder blends for uniformity under production conditions of long run times would be an important tool for the blended powder product manufacturer. In particular, the test sample must be of a uniform size to enable comparison of results between batches. Since production conditions typically require large quantities, deep bins are often used, and there is a need for a sampling device able to acquire samples from diverse areas of the deep storage bin.
Prior powder sampling devices and methods are disclosed in U.S. Pat. Nos. 5,337,620, 5,440,941 and 6,339,966 to the present inventor. The inventions disclosed in these prior patents acquire samples through laterally open cavities that are perpendicular to the axis of the sampler. Powder samples thus are subject to shear forces as the powder enters the cavity and are thus not totally reliable. The invention disclosed herein provides a novel sampler especially adapted for acquiring samples of blended powder from various positions in a bin by a cavity parallel to the sampler axis to ensure uniformity.